Film developing device



Nov.

w. J. HALL FILM DEVELOPING DEVICE Filed Feb. 19, 1954 l] lll/; LJ l United States Patent O FILM DEVELOPING DEVICE William J. Hall, Fort Worth, Tex.

Application February 19, 1954, Serial No. 411,455

3 Claims. (Cl. 95-90.5)

This invention relates to photographic equipment, and more particularly to an improved iilm supporting box to be used yin a film developing tank.

A main object of the `invention is to provide an improved lilm supporting box for use in a film -developing tank such as a daylight developing tank, the improved supporting box being simple in construction, being arranged to prevent contact `of the emulsion side of the lilrn with any surface, and being further arranged so that the lm is supported only on .its edge `as it is guided into the box.

A further object of the invention is Ito provide an improved -film strip supporting box for use in a daylight developing tank, said film supporting vbox being inexpensive to manufacture, being rugged in construction, being arranged to reduce the possibility of .fogging or contaminating the lm developing material or the emulsion side of the iilm, being easy to clean, and being provided with means for supporting the film strip inserted into the box on its edge and for preventing said strip from yengaging the surface 'of the recess in which the strip is guided.

Further objects and advantages of .the invention will become apparent from the following description and claims, and from the accompanying drawings, wherein:

Figure 1 is a top plan View of an improved lm strip supporting box according to the present invention, the cover of the box being removed.

IFigure 2 is a vertical'transverse cross sectional view taken through the film strip supporting box, according to the present invention.

Figure 3 is a vertical cross sectional View taken through a daylight developing tank in which is supported a lm strip supporting box according to the present invention.

Figure 4 is an enlarged vertical cross sectional detail view taken on Ithe line 4-4 of Figure l and showing in cross section a film strip supported in the box.

Referring to the drawings, the improved film strip supporting box is designated generally at 11 and comprises a generally circular main receptacle 12 having an upstanding peripheral wall 13 formed integrally therewith and being integrally formed with an upstanding spiral rib 14 equal in height to the peripheral wall 1B and being substantially concentric therewith. The spiral rib 14 has a substantial number of spiral turns spaced uniformly from each other to receive a strip of iilm to be developed and to support said lm strip between the turns, the spiral rib 14 terminating .at 15 near the center of the circular box. The bottom wall of the box, shown at 16, is formed with a central aperture 17 to allow developing liquid to enter the box. Designated at 18 is a circular cover having the depending peripheral flange 19, the cover being engageable on the top rim of the main receptacle 12 and the ange 19 being adapted vto frictionally engage over the top portion of the outer wall 13 of the main receptacle to provide a 4relatively close lit thereon.

Patented Nov. 20, 1956 ICC 'Ilhe bottom wall 16 iis formed with a plurality of additional -apertures 20 for the entrance of developing liquid. The top cover 18 is formed with a central .aperture 21 in which is loosely positioned a handle member having the shank 22, the lower enlarged portion 23, `and the top handle knob 24. The handle member has a relatively loose lit in the aperture 21, whereby ldeveloping liquid may flow freely through said aperture.

The surface of the bottom wall 16 is arcuately curved upwardly from the lower end of one turn of the spiral rib 14 to the lower end of the next 4adjacent turn, yas shown at 25, to prevent contact of the surface 26 of a lm strip 27 positioned in the `spiral groove defined by the spira-l rib 14, with the surface 28 of the rib opposite the surface 26. The surface 26 of the strip is the emulsion side thereof, and thus, the arcuately curved bottom surfaces 25 of :the spiral groove position the strip away from the surface 28 to prevent contact of the emulsion of the iilm with Ithe said surface 28.

ln using the box 1.1, the cover 18 is removed, and the box is loaded with the iilm to be developed, the emulsion side of the iilm being 'arranged adjacent the surfaces 28, which merge with the upper ends of the .arcuate surfaces 25. The film strip is fed into the box in the usual manner, inserting the tilm strip into the inner `end portion 30 of the groove 4.defined by the .spiral rib 14 and pushing the strip into the groove until the entire strip is received therein. As above explained, 'the arcuate bottom Walls 25 of the Igroove `serve to limit movement of the strip toward the surfaces 28 opposite ythe emulsion surfaces of the strip, and thus .act as guides for the bottom edges of the strip -to protect the emulsion .surface thereof against damage as the strip is being pushed through the groove or while the lilm is being wound .on the reel.

After the strip has been positioned in the spiral groove, the cover 18 is engaged on the main receptacle 12 and the box is then placed in the daylight developing tank, shown at 31, vfor processing the lilm.

The improved lilm strip supporting box above described may be obviously employed either for motion pictu-re film or yfor roll type lm employed to make still photographs. The improved lilm box of the present invention is especially advantageous for the processing of 8 mm., 16 mm., 35 mm., and 70 mm. aerial mapping The box may be made of any suitable inert material, and is preferably made of plastic material, such as clear plastic of the Lucite type.

'The reason for using clear plastic is to enable the tank to be employed for insuring an even re-exposure of the film. In the tank of the p-resent invention, made of clear plastic material, light impinging on any part of the clear plastic tank would circulate through the clear plastic and re-expose the iilm, even though only a limited area of the tank is exposed to the light.

`If the tank were made of opaque materia-l, such as metal, or of dark plastic material, a considerable amount of extra effort would be required if it were desired to re-expose `the film to light, .as when processing the reversible type of movie lilm, and especially is required when developing positive color film, which requires -reexposure on both sides. Thus if the tank were not made of clear plastic, such :as Lucite, it would be necessary to remove the color lilm from the reel, increasing the possibility of injuring the lm.

In the present invention, the reel is placed in the central space defined by the inner portion of the spiral rib 14, and the end slot in the reel is engaged by the depending projectons provided on the lower enlarged portion 23 of the handle shank 22. Thus by rotating the handle knob 24, the film may be pushed outwardly tank has been disclosed in the foregoing description, it v will be understood that various modications within the spi-rit of the invention may occur to those skilled in the art. Therefore, it is intended that no limitations be placed on the invention except as defined by the scope of the appended claims.

What is claimed is:

l. A lm supporting device for use in a daylight developing tank comprising a generally circular box, an

upstanding spiral rib of substantial height rigidly securedv `to the bottom wall of said box, ysaid rib being substantially concentric with the box and having a substantial -number of spiral turns spaced from each other to receive a strip of iilm to be -developed and to support said strip between the turns, said bottom wall being .apertured to allow developing liquid to enter the box, the sur-face of the bottom wall being arcuately curved upwardly from the lower end of one .turn `of the spiral rib to the lower end of the next adjacent turn to engage the bottom edge of the film strip and 4to prevent contact of the emulsion surface of the film strip with the surface of said next adjacent turn of the spiral rib.

2. A iilm supporting device for use in a daylight developing tank comprising a generally circular box having an outer upstanding peripheral wall, an upstanding spiral rib similar in height to said outer peripheral wall and rigidly secured to the bottom wall of said box, said rib being substantially concentric with the lbox and having a substantial number of spiral turns spaced from each .other to receive a strip `of lm to be developed and to support said strip between the turns, said bottom wall being apertured at its central land outer portions to allow developing liquid to enter Ithe zbox, the 4surface of the bottom wall being arcuately curved upwardly from the lower end of lone turn of the spiral rib to the lower end of the next adjacent turn to engage the bottom edge of the lm strip and to prevent contact of the emulsion surface yof the tlilm strip with the surface of said next adjacent turn of the spiral rib.

3. A iilm supporting device tor use in a daylight developing tank comprising a generally circular box having an `outer 4upstanding peripheral wall, fan upstanding spiral :rib similar in height to said outer peripheral w-all and rigidly secured to the bottom wall of said box, said rib being substantially concentric with the box and having a substantial nlrmber of spiral turns spaced from each other to receive a strip of iilm to be developed and to support said strip between the turns, said bottom wall being apertured fat its central .and at its outer portions to allow developing liquid to enter the shox, the surtace of the bottom wall being .arcuately curved upwardly from the lower end of one turn of the spiral rib to the lower end of the next adjacent turn to engage the bottom edge of the tllm .strip and toprevent contact of the emulsion surface of the iilm strip with the surface of said next adjacentt-urn of the spiral rib, ya circular cover engagedk on the top r-im of ysaid box, said cover having a depending peripheral 'ange frictionally engaging over the top portion of .said outer wall, said cover having a vcentral aperture, and a handle member loosely secured in saidy last-named aperture.

References Cited in the le of this patent UNITED STATES PATENTS `1,012,723 Seeley Dec. 26, 1911 2,1ll2,606, yPless Mar. 29, 1938 2,218,392 `Chafvin Oct. 15, 1940. 2,334,952 Perbal NOV. 23, 1943 2,527,626 Forssell Oct. 31, 1950 FOREIGN PATENTS `618,399 France July 1, 1926 494,266 Great Britain 0015.24, 1938 550,726 Great Britain Ian. 2l, 1943 

